Does anyone find it odd that Starfleet happens to moblize a fleet to take Torros and combat the pending Dominion invasion of 2373 AND repel the Borg incursion of Sector 001 AT THE SAME TIME?
Surely the Dominion was aware of the Borg's presence and picked such a ripe time to attack. I theorize their heads have bumped before, and the Dominion is still standing :-D!
Are you talking about the battle in Call to Arms? If so, Sisko mentions the Borg attack in Blaze of Glory, an episode that's well before Call to Arms. So no, they didn't do it at the same time. If you go by stardate, then First Contact is still three episodes before the Torros.
Rough estimates for the Battle of Sector 001 say Starfleet battled the Borg (one ship!) for days. That was one vessel. The battle of Torros couldn't have lasted more than a day (or else the Dominion would've sent reinforcements).
Of course, perhaps Starfleet was better suited to fight the Borg because the Dominion had them at high alert for so long, giving Starfleet enough time to draw a huge number of their combat-ready ships.